As shown in FIG. 1, in a carrier's carrier (carrier's carrier) solution in the prior art, an internal gateway protocol (Internal Gateway Protocol, IGP)+a label distribution protocol (Label Distribution Protocol, LDP) are utilized between a customer equipment (Customer Edge, CE) of a backbone carrier and a provider edge equipment (Provider Edge, PE) of the backbone carrier. PEs inside the backbone carrier use a boarder gateway protocol (Border Gateway Protocol, BGP) to advertise a route and a label of a customer carrier. A PE equipment of a customer carrier, which is a customer carrier provider edge equipment (customer provider edge, C-PE) in FIG. 1, needs to establish a label switched path (Label Switched Path, LSP) from a C-PE2 of an upstream second customer carrier to a C-PE1 of a downstream first customer carrier in order to be able to provide its customer with a virtual private network (Virtual Private Network, VPN) service.
IGP+LDP protocols run in an internal network of the backbone carrier and run between a customer equipment CE1 and a PE1 equipment of the backbone carrier. On the PE1 equipment, both protocols belong to a virtual routing and forwarding (Virtual Routing and Forwarding, VRF). An LSP from the PE1 to the C-PE1 is established via the LDP. The PE1 learns a route to the C-PE1 via the IGP.
In a VRF instance on the PE1 equipment of the backbone carrier, the IGP route in the VRF instance is introduced into the BGP VPN, which uses the BGP to advertise a route (a route from the CE1 to the C-PE1) of the customer carrier to a PE2 equipment of a remote backbone carrier. When advertising a private network route, the BGP allocates a label for each route in a per-route per-label method and advertises a route together with the label allocated for the route to the PE2 equipment via the BGP. The PE1 takes a label of the route allocated by the CE1 for the PE1 via the LDP and the PE1 locally. A multi-protocol label switching (Multi-Protocol Label Switching, MPLS) is a technique used for fast packet switching and routing, it provides network traffic with capabilities such as targeting, routing, forwarding, switching and etc. In the MPLS, data transmission occurs on an LSP, reasonable establishment of the LSP can greatly reduce cooperation between different network layers when services are deployed, thereby improving a forwarding speed. Thus, how to establish the LSP reasonably is critical for a carrier to quickly provide services and lowers service deployment costs.
Seamless (Seamless) MPLS networking refers to a networking manner that all internet protocol (Internet Protocol, IP) devices managed by carriers, including access network devices, convergence network devices and backbone network devices, form a unified IP/MPLS control plane. Currently, in a solution of an IP radio access network (Radio Access Network, RAN) based on the seamless MPLS, when an access network integrates with the IP backbone network, the access network stitches (Stitch) with a border gateway protocol (Border Gateway Protocol, BGP) LSP established by the IP backbone network mainly via an LSP established by the label distribution protocol (Label Distribution Protocol, LDP), thereby completing an integration of the access network of the IP RAN with the IP backbone network. During this process, a node device in the access network needs to statically configure a route reaching a BGP LSP destination device in the IP backbone network; the static configuration of the route is complicated, which thereby increases difficulty of maintenance and management of node devices.